Process of treating coffee and preserving its flavor



May 17,1938. A. J. HAZLE. JR 2,113,010

PROCESS OF TREATING COFFEE AND PRESERVING ITS FLAVOR Original" Filed 001;. 24, 1951- 2 Sheets-sheaf 1 Z 5 E F 15126 FE U May 17, 1938.

PROCESS OF TREATING COFFEE AND PRESERVING ITS FLAVOR Original Filed Oct. 24, 1931 2 Sheets-Sheet 2 2 %nnmnnnnnnnnnnunnManama EWEF.

A. J. HAZL'E, JR 2,118,010

UNITED STATES PATENT. OFFICE PROCESS OF TREATING COFFEE AND PRE- SERVING ITS FLAVOR Albert J. flazle, Jr., Chicago, Ill., assignor to B. F. Gump Company, Chicago, 111., a corporation of Illinois Original application October 24, 1931, Serial No. 570,863. Divided and this. application August 9, 1937, Serial No. 158,078

3 Claims. (Cl. 83 -18) This invention relates to a process for treating action as to not only effect a thorough comminucoflee and preserving its flavor after the coffee tion of the chaff and coffee particles but in adhas been suitably ground or granulated, and dition thereto to prevent any liberated free chaff more particularly to a process of treating ground from being ejected or carried off of the coffee coffee containing flaky chaff so as to break up mass at the discharge point and to cause the 5 thoroughly the relatively large free particles of finely comminuted chaff to be colored by coffee coffee chaff and to render the same substantialoil by reason of the rubbing of such chaff parly invisible in the ensuing product. ticles of the mass.

In the past it has been the practice to use In addition thereto I aim to provide a process 10 plate mills for producing fine grinds of coffee, of treating coffee produced on a roll mill in such 1 and roll mills for producing steel cut coffee cona way that not only will the chaff therein be sisting of small, sharp granules with very little thoroughly comminuted but in addition thereto powdered coffee. A plate mill in producing its the mass will be at all times subjected to a back usual fine grinds will simultaneously reduce the pressure so as to prevent or minimize the pos chaff, as fine as the coffee. The powdered prodsibility of air currents or the like arising from 15 net or flour coffee it produces is not satisfactory the Whipping action l w n he li r d n for many methods of brewing coffee. free chaff from the coffee mass.

0n the other hand, when the so-called roll type Another and further object of this invention is of mill is employed for cracking and breaking to provide a process for treating coffee which has up the coffee beans, it has been found that while been first cracked and then granulated in a roll go the ensuing product has coffee particlesof relamill in such a manner as aforesaid that not only tively uniform size, considerable quantities of is it possible to comminute thoroughly the chaff coffee chaff are present in the product by reason in the coffee mass but in addition thereto it is of the fact that the chaff is not broken up to possible to blend the coffee mass and chaff toany substantial extent as is the case in a plate gether in the presence of the gases set free dur- :5

mill. However, coffee which has been broken ing the cracking and milling of the coffee beans up or granulated in a roll mill has been found so that substantially the original flavor of the to be more satisfactory for the making of coffee coffee may be preserved in the ultimate product. beverage on account of the fact that the particles In accordance with the features of the present are more uniform and enable better extraction. invention, there is provided a process of preparso However, in view of the fact that coffee produced ing coffee which has been first cracked and then upon a roll mill contains a considerable amount granulated in a roll mill and which coffee inof flaky chaff, it has heretofore been necessary cludes coffee particles of relatively uniform size to remove the chaff, then comminute the same, .as well as relatively large flakes of chaff, which and then return the same to and mix it with 'process consists in propelling the coffee mass thus the granulated coffee. This involved a long, formed in a continuous stream along a given laborious, and expensive process. path, contemporaneously subjecting the mass to Now it is the aim of my present invention to a rapid agitation or high speed impacts to comprovide a process of treating granulated coffee, minute and concealthe chaff and breaking up 1 i such ashas been ground in a roll mill, and which the centrifugal flow of the coffee mass so that 4 contains fiaky chaff, so that the chaff will be the mass willnot rotate as a unit but will be comminuted and concealed without the necessity thoroughly agitated and commingled. of first removing the chaff and'then separately My novel process is, further characterized by grinding the same. I accomplish this by subjectthe feature of subjecting the forwardly moving 4' ing the coffee mass including the coffee particles mass to a back pressure of a predetermined of relatively uniform size and thelocse flakes of amount adapted to be' overcome in response to chaff to a rapid agitation or high speed impacts the discharge pressure of the coffee mass but while at the same time breaking up centrifugal suflicient to enable the coffee particles and chaff fiow of the coffee mass whereby the coffee par: of the mass to bear frictionally'against each other 0 ticles are polished or secured and the fragile to color the chafi with the liberated coffee oil and flakes cf chaff are finely comminuted and to effect substantially a complete comminution blended with the coffee to a substantially invisof the chaff by the c'ofi'ee particles. This back ible state. pressure is particularly advantageous in that it It is also an object of my invention to subject substantially prevents air currents occasioned by coffee ground on a roll mill to such a whipping the propulsion of the coffee mass and the whip- 5" ping of the same from carrying off of the cofiee mass about to be discharged any liberated particles of chaff which may lodge on or adjacent the end of the top of the mass.

Still another feature of my invention relates to the agitating of the mass in a substantially closed path or zone so that the coffee mass being treated in the ensuing product loses substantially none of its aroma.

Other objects and features of this invention will more full; appear from the following detailed description taken in connection with the accompanying drawings. It is believed that my novel process will be fully understood from a description of an apparatus by which it may be practiced, which apparatus is fully disclosed in my copending application Serial No. 570,863, filed October 24, 1931. Accordingly, it will be appreciated that the subject matter of my present process has been divided from my aforesaid c0- pending application.

In the accompanying drawings which illustrate a preferred form of apparatus in which similar reference numerals refer to similar features in the different views:-

Figure 1 is a part elevational and part sectional view of an apparatus involving this invention for carrying out my novel process.

Figure 2 is a top plan view of theagitating part of the apparatus'with parts removed.

Figure 3 is a fragmentary sectional view taken upon the line 1IIIII of Figure 1 showing details of a type of roll mill which may be used to grind the coffee beans.

Figure 3A is an enlarged fragmentary cross sectional view of the agitating device taken on the lines 3A--3A of Figures 1 and 2 and showing the non-circular contour of the top of the agitating chamber.

Flgure 4 is a fragmentary cross sectional view through a modified form of agitating apparatus.

Figure 5 is a fragmentary longitudinal sectional view through a still further modified form' of agitating apparatus.

Figure 6 is an enlarged detail sectional view showing a device for enabling the practicing of my novel back pressure steps.

Figure 7 is an enlarged sectional view taken upon the line VIL-YH of Figure 5.

Since this invention is not primarily concerned with what steps are employed in the grinding or granulating of the coffee beans, it will be appreciated that any suitable mill may be used for cracking the cofl'ee such, for example, as a roll mill, one form of which I have illustrated in Figures 1 and 2. In these figures, there is illustrated a roll mill A which first cracks the roasted coffee beans, then granulates the same into a coffee mass consisting of coffee particles of relatively uniform size and particles or flakes of chaff of substantial size.

'The roll mill A is illustrated as being part of an apparatus which includes supporting legs or standards I upon which an agitator B, comprising a drum or casing 2, is mounted having a discharge spout 2" at its outer or discharge end which communicates with the interior of the casing at a point above the bottom thereof as shown in Figure 3A so that an accumulation of the reduced mass may take place therein. Extending longitudinally through the casing and journalled in suitable bearings thereon is an agitating'shaft 3 from whichextend in radial directions agitating or impact pin members 4 which are spaced spirally of the shaft about two inches apart The tion between the particles of coffee and the par- .ticles of coffee and chaff may be attained for producing an even uniform mixture in which the chaff is thoroughly comminuted and concealed in the coffee product.

At the outlet C (Fig. 3A) of the drum 2 there is a door or gate I 3 (Figure 6) to which a curved stem I4 is attached that extends through an aperture in the wall of the spout and that is equipped with a weight ii at its outer end for urging the door toward its closed position. The door I3 is hinged upon'a rod It at its upper margin. This gate, as will be described more fully hereinafter, will tend to restrict-the flow of the finished product from the drum 2.

The granulatingmill A is mounted upon the drum 2 of the agitator B and discharges the granulated mass through and directly into the top of the drum 2 adjacent an end thereof. This granulating mill A consists of a suitable and substantially airtight casing 5 in which are journalled a pair of vertically spaced corrugated cracker rolls '6 that cooperate with adjacent cracker bars 1 for breaking down the coffee beans. Below the cracker bars I there are a pair of cooperating granulating rolls 8 and 9. These rolls may be driven by any suitable mechanism. The agitating shaft 3 is preferably connected by sprocket gearing Ill to one of the shafts of the rolls 8 or 9.

In Figures 4 and 5, a modified form of agitating pin has been illustrated. This modified form of pin which is represented by the reference 4 is provided with a blade III at its outer end which may be set at a suitable angle to the axis of the agitating rotor to convey and expedite the movement of the mass toward the outlet and thuswise prevent heating of the mass more quickly and to clean out more thoroughly the cylinder of its cofiee product. The stems 4 are preferably threaded in the shaft 3 so that the blades can be adjusted to any desirable angle and at a suitable distance from the wall of the drum. A gauge plug I! (Figure 7) may bescrewed in the shaft 3 opposite the end of each stem 4 to regulate the effective lengthsof such stems. The casing 2 is adapted to be closed except directly under the mill 5. A cover i I (Figure 4) having an interior' concave surface I! to prevent the coffee product from lodging in the corner of the casing maybe used to close the top of the casing.

A cleaning out outlet is provided in the bottom of the drum and this outlet is normally closed by a slide l8 which may be shifted or removed to uncover the outlet at the end of a run or when it is desired to clean out the drum so that the accumulations below the discharge gate'may be readilyremoved.

In the operation of this apparatus, the coffee beans are put into the mill A and arecracked by the two cracker rolls and bars and granulated by the rolls 8 and 9. Most of the chaff is liberated in flakes of substantial size by these rolls and the combined chaff and coffee particles descend as a mass directly into the :drum 2 of the agitator B in which the agitating shaft rotates at a. high rate of speed. It will propelled coffee mass to a be noted that the mill A.

is positioned adjacent the end of the drum 2 which is remote from the spout 2 with the result that the granular mass and the chaff will travel in a given path or zone through the drum towards the spout 2 through which it will be discharged. The rapid rotation of the pins will cause the proper attrition of the particles of coffee and thoroughly comminute the chaff which is mixed with the coffee through a whipping and scouring action so that the chaff is practically concealed in the product that issues from the spout 2 and a uniformly blended and mixed product is obtained.

It will be appreciated that this method and apparatus eliminates the use of sieves, chaff re moving means, chaff grinding means, and tailings conveyor that were heretofore necessary in making steel cut coffee.

From the foregoing description, it is, therefore, apparent that a coffee which has been cracked and granulated is transmitted directly to the mixing or comminutlng chamber of drum 2 which has a closed connection with the housing 5 in which the roll mill is enclosed. As a consequence, any aromas or gases, such as CO2 gas, liberated during the breaking up of, the coffee beans, are allowed to permeate the forwardly propelled mass in the comminutlng chamber 2. This insures preservation of the original flavor of the coffee.

It will also be noted from Figures 2 and 3A that chamber 2 has a non-circular top wall which enables the centrifugal flow of the agitated coffee mass to be broken up so that the mass will not rotate as a solid unit and will thus be subjected to a thorough agitating and communiting action.

In addition thereto, by reason of the rapid movement of the pins or comminutlng elements 4-4", as well as the fact that chamber! is of such shape as to break up the centrifugal flow of the coffee mass, the relatively large flakes of chaff which have been liberated during the coffee cracking operation are thoroughly comminuted in the coffee mass. Moreover, this coffee mass does not have any substantial amount of powderlike substance such as is objected to when the cofiee is broken up in a plate mill.

By reason of the rapid whipping action of the comminutlng elements, the coffee particles are scoured or polished contemporaneously with the comminutlng of the flakes of chaff. In addition thereto, the flakes of chaff are caused to be frictionally pressed against the coffee particles so that the comminutlng of such chaff also enables the chaff to be colored to a considerable extent by the coflee oils present in the forwardly moving mass. It, therefore, follows that not only does the finely comminuted chaff thoroughly commingle with the mass, but in addition thereto, it is rendered substantially invisible in the ensuing product.

.I have found that by subjecting the forwardly back pressure variable in response to forward movement of the mass it is possible to prevent any air currents circulating through the comminutlng chamber of drum 2 from carrying out of the chamber free particles of chaff which may get to the top of the mass. This feature is effected by the use of the gate or valve 13 which is subjected to the pressure of a weight 15.

It will be appreciated that the weight l5, as well as the leverage of the hinged gate, applies a predetermined pressure against any laterally ejected coffee mass that may be pressed against stream throughout commingle the chaff with the door through the discharge opening shown at C in Figure 3A. In other words, until a predetermined quantity of coffee mass has accumulated at the discharge opening C sufficient to overcome the pressure exerted by the gate l3 and its weight l5. no discharge of material from the drum 2 is effected. However, after a suflicient amount of the material has accumulated in the opening C to overcome the pressure of the gate and its weight 15. it will be evident that the'gate will swing open and allow a discharge of the material. This discharge is, of course, an intermittent one, since after each discharge of a given quantity of material. sufficient time must elapse for an additional quantity of material. to build up against the gate and in the opening C for again overcoming the pressure of the gate.

This feature is highly advantageous in that it precludes any possibility of loose or free chaff in the vicinity of the discharge opening C from being blown out of the opening prior to such chaff having had an opportunity to .be properly comminuted and commingled in the coffee mass. By reason of the aforesaid holding back of the coffee mass, a much more thorough and complete comminution of the chaff in the coffee mass is made possible. Then, too, the gate l3 enables the agitating chamber of drum 2 to be closed so that the agitating, mixing, and comminutlng actions take place in a closed area or zone whereby the coffee mass loses substantially none of its aroma.

Another advantage of my invention resides in the fact that the process increases the density of in smaller containers than would have been feas- I ible prior to the subjecting of the ground coffee to my novel process of treating the same. In this respect, it will be appreciated that a considerable saving can be effected since my process enables the ensuing product to be sold in smaller packages than would otherwise be feasible.

I am aware that numerous details of the process may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

l. The process of preparing coffee that has been broken up into coffee particles of relatively uniform size as well as into particles of chaff which includes the steps of propelling the coffee mass thus formed in a continuous stream along a given path of substantial length longitudinally to an axis and simultaneously causing said stream to flow centrifugally about said axis while being subjected to a beating action, the centrifugal flow being broken up along the periphery of said a substantial portion of the length of said path to cause relative movement between the coffee particles and liberated chaff at the place of interruption so as to subject the particles of chaff to such an abrading action by the rotating coffee particles as to reduce and the coffee particles into a product in which the chaff is substantially concealed.

2. The process of preparing coffee that has been broken up into coffee particles of relatively uniform size as well as into particles of chaff which includes the steps of propelling the coffeestantlal portion of the mass about said axis and subjecting it to a beating action while at the same time interrupting the free rotation of a peripheral part of the whirling mass through a substantial part of said path to cause relative movement between the coilee particles and liberated chaff at the place of interruption so as to subject the particles of chafl to such an abrading action by the rotating coifee particles as to reduce and commingle the chaff with the coffee particles into a product in which the chaff is substantially concealed, maintaining the discharge end of said path closed under a back pressure and overcoming said back pressure to open the discharge. end of the path by the pressure of accumulated coil'ee in the path whereby to prevent particles of free chafi from being prematurely discharged from said path. 7

3. A method of treating roasted coffee beans, including the following steps: first granulating the coflee beans, and second working substantially all of the granulated coffee and any liberated chafi together for a period of time sufficient to pulverize the chaff and commingle it with the coffee, said working including the steps of propelling the granulated cofiee mass in a continuous stream along a given path of substantial length longitudinally to an axis and contemporaneously rotating a substantialportion of the mass about said axis and subjecting it to a beating action, while at the same time interrupting the free rotation of a peripheral part by breaking up the centrifugal flow of the whirling mass through a substantial part of said path to cause relative movement between the coifee particles and liberated chafi at the place of interruption. whereby the chafi is substantially concealed.

ALBERT J. HAZLE, JR. 

